Mechanism of upright pianos



Sept. 22, 1925. 1,554,977

O. P. BORGARELLfi MECHANISM OF UPRIGHT PIANO$ Filed Marsh 15, 1923 INVENTOIQ Oc'ygayo PEOEGAJEEZLQ Patentedsept. 22, 1925,

UNITED STATES OCTAVIO PIOVA'NO BORGARELILO', OIE BUENOS AIRES, ARGENTINA.

MECHANISM OF UPRIGH'J. PIANOS.

Application filed. March 13, 1923.

To all whom it may concern:

Be it known that I, OOTAVIO PIovANo BoReAnnLLo, a subject of the King ofItaly, residing at Calle Maipu 671, Buenos Aires, Argentine Republic, have invented new and useful Improvements in the Mechanism of Upright Pianos, of which the following is a specification.

This invention relates to certain improvements which I have introduced in a part of the mechanism of upright pianos usually known as the pianoforte action, for the purpose of simplifying the construction of such mechanism and especially to obtain a more perfect and rapid repetition of the hammer stroke on the wire.

As will be hereinafter seen, the pianoforte action which is the subject of this invention presents many improvements over those heretofore known in the art, but the most important of them is the spring controlled ack, since the special and improved construction of the same permits the execution of a tremolo or repetition of the note, with much greater rapidity and exactness than by former methods.

I will describe my invention with reference to the accompanying drawings illustrative of a preferred form of construction of the same, and in which:

Fig. 1 is a sectional view representing an upright pianoforte action embodying the features of my invention.

Fig. 2 shows the same mechanism at the moment when the system for the momentary retention of the jack is in operation.

Fig. 3 is a perspective view of the jack check with a groove provided in the wood of which it is formed, and with a spring.

Referring to the drawing the pivoted hammer butt 3 carrying the hammer 20 is weighted as at 5, the weight preferably consisting of lead set in a mortise in the butt. The butt 3 is connected to the check 13 by the cord 11 and engages the spring secured to the check and having its free end engaging a recess in the felt 19 of the jack.

The check 13 is provided with a groove 14 designed to receive and lodge the spring 15, and a notch 16 in one side where the cord 11 is lodged and held.

The object which I have sought for in the invention of this novel form of check 15 is that of securing a more perfect rapid repetition or tremolo of the note, which Serial No. 624,790.

is accomplished by means of the action of the spring 15 resting on the felt 19 and which sends the jack under the salient of the butt 3, thus retarding the fall of the hammer 20 and facilitating the above mentioned operation.

The screw 21 permits the graduation of the force of the spring 15.

The above described simplifications are of an economical order and at the same time give greater duration to the general mechanism due to its greater simplicity.

As may be seen in Fig. 2, at the moment when the return movement of the hammer begins, the spring 15 detains its movement during the fraction of time necessary for the jack to again lodge in the butt, thus permitting the repetition of the note. By this means a very rapid and perfect repetition is secured, as otherwise, on depressing the key it would have to rise approximately more than one tenth of its complete movement in order to produce anew the lodging of the jack and the repetition of the note.

Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States of America is:

1. In a piano mechanism, a jack, a hammer butt, a check, and a spring carried by ti e check and conn cted with the jack and with which the hammer butt is adapted to engage.

2. In a piano mechanism, a jack, a hammer butt, a check, a flexible connection between the cheek and butt, and a spring carried by the check and connected with the jack and with which the hammer butt is adapted to engage.

3. In a piano mechanism, a jack, a hammer butt, a check having a longitudinal groove, and a spring having one end secured in the said groove, said spring projecting out of the groove and having its other end connected with the jack and with which the hammer butt is adapted to engage.

4;. In a piano mechanism, a jack, a hammer butt, a check having a longitudinal groove, a spring having one end secured in the groove, said spring projecting out of the groove having its other end connected with the jack, and with which the hammer butt is adapted to engage and means for adjusting the spring.

PIOVANO BORGARELLO, 

